Non-destructive fault induction in an electro-hydraulic servo system

This paper aims to solve the problem of high research expense on the fault implementation of electro-hydraulic servo (EHS) systems. Due to high integration and high sensitivity of the system, any failure induced in it may cause the whole system crashed. This makes the fault implementation high risk. In order to make the research on fault diagnosis easier, a non-destructive approach is developed in this paper. On a test rig, several kinds of faults are implemented by adding additional circuits in the system. The first one is implementation of circuit failures in the torque motor coils of the EHS valve. It is carried out by means of a switch circuit, The second kind of fault is leakage of the actuator, which is carried out with a parallel loop to the main supply loop of the actuator. All these faults or failures are repeatable without any destroy in the system itself. The test results have been given at the end of this paper. The results show that this is an economical way and provides researchers in this field a convenient approach in fault analysis of EHS systems.